Trinuclear heterometallic complexes

Nickel forms organometallic clusters with three to six metal atoms. Among these some unusual structures and bonding situations occur which were mentioned in Chapter 2. The cluster chemistry of palladium is rather poor, and the outstanding features of platinum are a considerable number of trinuclear heterometallic complexes and the chimney-like structures of the clusters [Pt3(C0)g]. ... 

The so-formed mononuclear cobalt species has been used further as a tridentate ligand in the synthesis of a series of trinuclear heterometallic complexes of the following type [404,435] ... 

The reaction of silver perchlorate with the complex [Au(C6F5)(Ph2PCHPPh2Me)j gives the trinuclear heterometallic cationic complex [ (C6F5)AuPh2PCH(PPh2Me) 2Ag CIO4 [84]. 

Replacement of the Au(PR3)C1 molecule by the AuC12 anion in reactions with transition metal anions gives rise to linear trinuclear Au-M-Au heterometallic complexes, as in the reactions (234)... 

The interest for pyrazolate complexes containing the pz group as a mono-dentate ligand arises because of their recognized usefulness in the synthesis of dinuclear and trinuclear heterometallic derivatives. The mononuclear complex... 

Nickel(II) complexes with various sulfur-nitrogen chelating ligands are reported in Table 100. 2-Aminoethanethiol (HL) is the simplest representative sulfur-nitrogen ligand acting as an anionic chelate. It forms two types of nickel(II) complex, namely the bis chelate [N1L2I and the trinuclear Nial Ct (333). Both complexes are square planar. Heterometallic complexes similar to (333), [MCNil W", have been reported with different metals such as M = Cu, Cu", Pd +, and Most of the complexes with 2-aminoethanetbiol have been... 

The complex is a good nucleophile and reacts with acids (e.g., CF3C02H) and methyl iodide to form the corresponding salts of the cations [ 0(1 -CsHs)(P(OMe)3)2R] (R = H, Me). Thermolysis gives the super-sandwich complex [Co3( /-C5H5)2( -P(OXOMe)2)6], which is an important starting material for the syntheses of heterometallic di- and trinuclear phosphonatemetal complexes. ... 

For example, the prototypical molecule from our lab, CrCrFe(dpa)4Cl2 (3 13, Scheme 14), was synthesized so that we could understand how the presence of an axial heterometallic Cr Fe interaction affects the electronic structure of the Fe(II) ion [63]. This molecule could be synthesized via a general two-step strategy from Cr3(dpa)4Cl2. Cr3(dpa)4Cl2 and excess sodium cyanide react to extract one of the Cr atoms from the trinuclear chain to yield Cr2(dpa)4, which can then react with another metal source, here FeCl2 is used, to produce the heterometallic complex [63]. 

Other work involving complexation of ferrocenylphosphines include the preparation of silver complexes of diferrocenylphosphine a trinuclear dirhenium complex dppf as a spacer ligand between rhenium centres dppf in gold complexes palladium and platinum complexes from the carboxylation of [(dppf)MCl2], M = Pd, Pt complexes technetium and rhenium heterometallic complexes mixed silver/nickel complexes ... 

As the data summarized in Tables I and II show, both Pd (II) and Co (II) form homometallic trinuclear complexes of the general structure[M (ML2)2]X2. Also, the mononuclear Pd (II) complex has been utilized to form heterometallic trinuclear species—e.g., [Ni(PdL2)2]X2. 

The trinuclear zirconocene-aluminum heterometallic hydrido complex [Cp2ZrH(//-H)2]3Al 652 was isolated in low yield from the reaction of Cp2ZrCl2 with LiBH4, LiAlH4, and a catalytic amount of Cp2TiCl2 (Equation (40)). The molecular structure of this complex has been determined by X-ray diffraction analysis, featuring the distorted octahedral Al geometry.474... 

The title complexes, CpM(PMe3)2 and CpM[P(OMi )3]2, are electron-rich half-sandwich complexes that have been demonstrated to be valuable precursors to a large number of organometallic derivatives. They behave as Lewis bases and react with a wide variety of electrophiles E or EX to form new metal-element bonds. They have also been shown to be valuable starting materials for the syntheses of heterometallic di- and trinuclear complexes via their reactions with unsaturated transition metal compounds. The only viable syntheses of these compounds now known are those reported here. 

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